Attachment-plug.



C. D. PLATT.

ATTACHMENT PLUG. APPLlCATlON FILED Aue.2s.1914.

Patented July 6, 1915.

llVI/E/VTOR WITNESSES V. M M U A T s '1 a 4!. I f

CLARENCE D. PLATT, OF BRIDGEPORT, CONNECTICUT.

ATTACHMENT-PLUG.

Specification of Letters Patent.

Patented July 6,1915.

Application filed August 28, 1914. Serial No. 859,024.

To all whom it may concern:

Be it known that I, CLARENCE D. PLATT, a citizen of the United States of America, and residing at Bridgeport, in the county of Fairfield and State of Connecticut, have invented new and useful Improvements in Attachment-Plugs, of which the following is a specification.

This invention relates more particularly to swivel plugs, and one of the main objects of the invention is to provide a plug of this character which can be quickly separated or assembled wholly by hand, for the purpose of attaching or detaching the wires and which may be readily wired.

Qther objects are to provide an attachment plug of small, convenient size, neat appearance, simple, sturdy construction, and high current carrying capacity.

Briefly considered the invention contemplates the provision of an insulating base carrying the circuit terminals and one socket terminal and a second insulating member carrying the other socket terminal and a manually releasable catch for rotatably con-.

fining such parts to each other, the catch having an exposed finger hold for operating the same. Usually the catch is carried by the base and engaged with a locking flange on the end of the surrounding socket shell contact and the finger hold for operating the catch is extended down below the flange to an exposed point at the contact end of the plug. Protection against possible shock may be alforded by insulating the catch from the current carrying parts of the memher on which it is supported.

Other important features of the inve 'ltlOll will appear as the specification proceeds.

In the accompanying drawing I have illustrated in concrete form apractical em bodiment of the invention, but as this is for illustrative purposes it will be understood that various changes and modifications may be made without departing from the true spirit and scope of the invention.

Figure 1 is a longitudinal section view of an attachment plug exemplifying my invention. Fig. 2 is a drop perspective view of the several parts of the plug separated. Fig. 3 is a transverse sectional View through the terminal-carrying insulating base taken substantially on the plane of the line 33 of Fig. 1. Fig. 4- is a detail plan view of the combined circuit terminal and contact ring in the blanked-out form and before'the terminal post portion has been bent up into its final position. Fig. 5 is a detail side view of a modification of the circuit terminal-carrying member.

In Figs. 1 and 2 of the illustration, the in sulating terminal carrying base is made in two parts, a main body member 8 and a lower cap member 9, the two parts being held together'by a screw 10. The head of this screw or a washer, such as indicated at 11, clamped beneath the same, serves as the end contact of the plug for engagement with a central socket contact.

The cap member is formed with a central opening 12 therethrough and the body member has a corresponding opening 13 in its lower end, the two constituting, when the base members are assembled, a central bore for the reception of the securing screw. At its upper end the securing screw engages in a screw seat provided in the angular foot 1% of the circuit terminal 15. This circuit terminal seats in a longitudinal recess 16 provided in the side of the body member 8 and the angular foot of the terminal is received in a transversely extending passage 17 which, as shown, communicates with the central bore. The screw seat is so positioned on theterminal foot as to aline with the central screw passage when the terminal is mounted in proper position on the base. In this way a single screw serves to secure the two parts of the base together and to fasten the end contact and its circuit terminal upon the base.

The other socket contact of the plug is in the form of a shell 20 surrounding the base and inclosing the circuit terminal carried thereby. In the specific form illustrated, this contact is a screw shell suitable for engagement with an ordinary Edison socket, and it is shown supported on and carried by a sleeve 21, of suitable insulating material, the shell having threaded engagement over the lower end of the sleeve and the upper end of the sleeve being enlarged into a head 22 serving as a hand hold.

The screw shell member and the terminalcarrying base member are rotatably secured together by a catch on one of said members interlocking with a flange on the other member. In the illustration the screw shell car- .ries the flange and the catch is mounted on at the lower or forward end of the screw shell.

The locking device which cooperates with the locking shoulder is illustrated in the present disclosure as a spring catch having a relatively broad base portion 27 by which it is secured upon the insulating base and a harrower portion 28 which is doubled back upon itself to constitute a spring arm and is provided with an outwardly projecting locking shoulder 29 and with a finger hold 30' below said locking shoulder. The locking shoulder is preferably formed with an inclined upper surface and with an abrupt lower surface, substantially as shown, so that in the assembling of the parts, the edge of the locking flange will ride down over the incline, and thus gradually depress the looking spring until a point isreached where the spring snaps the shoulder over the top of the locking flange, and thus positively secures the parts together. The finger hold 30 extends down below the locking flange of the shell and is exposed so that it can be readily operated by hand. In the case illustrated, this finger hold which forms a handle for manually releasing the locking catch, extends down into a peripheral recess 31 provided in the cap or flange portion of the insulating base. The finger hold is thus fully exposed for the purpose of operating the same and at the same time is protected against accidental operation.

The locking catch may be secured upon the base in various ways and in the present instance it is for the sake of simplicity and certain mechanical advantages supported and carried by one of the circuit terminals. This other circuit terminal is designated 34 and is of novel construction in that it has an integral base portion in the form ofv'a ring 35 which is contacted by and carries current to the locking flange of the shell."

This contact ring in the illustration rests upon the flange or cap portion of the base and constitutes an angularly outstanding abutment or contact shoulder for the end flange of the screw shell to bear upon.

The construction of the combined contact ring and terminal post will be best understood from Fig. 4 wherein it will be seen that the exterior of the ring is in the form of a true circle and that the terminal'post is formed from the metal inside the ring, being blanked out and then bent up out of the plane of the ring. In blanking out, the terminal post is left connected with the inner rim of the ring at 36, the surplus metal being removed at opposite sides of the terminal post portion as indicated at 37 and the head of such portion being discon nected from the ring by shearing it along the line 38. This shearing in place of a blanking out action at this point saves all the metal needed to form a substantial head at the point where the wire is to be connected to the terminal post. This shearing action may follow or take place simultaneously with the blanking out. After being thus blanked out and separated from the contact ring at all but the one point, the terminal post is bent up on the line 39 substantially' at a right angle to' the plane of the ring. The base portion of the terminal post is usually blanked out relatively wide as indicated at 40 to provide a broad base for the anchorage of the spring catch there to and at the foot of the terminal post portion there is preferably punched out an opening 41 for the'passage of the finger hold. The contact ring is preferably made of sheet metal, such as brass, so that it'can be readily worked into the form desired.

Suitable fastenings may be employed for securing the spring catch in place, and where, as in the present-instance, the said catch is supported by a circuit terminal, the metal of such terminal may be formed up into integral hollow rivets 43 engaged with the widened base portion of the spring catch. v

In order to relieve the spring catch from carrying current, when this is desired, 1. have shown means for insulating it from its support in the shape of an insulating sheet 45 interposed between the base of the catch and the support and surrounding the fasteir ings 43 and washers 47 placed beneath the heads of such fastenings. ,The insulating of the catch, by relieving it from'carrying current, protects it from injury by heating, and at the same time protects one operating the plug from injury by shock, in the case where the conductors from the plug are connected with a source of current.

In the case described, where the catch is carried by the circuit terminal and is insulated therefrom, the guard opening 41 in the contact ring is made of such a size that the finger hold passing therethrough,;will

not, in the ordinary manipulation thereof, contact with the ring: By passing the finger hold in thisway down through or at a point inside the periphery of the ring the finger hold and hence the catch is protected from mechanical injury during shipment, &c.

o The body portion of the base is usually recessed or flattened somewhat, as indicated at 50, to receive and form a backing for the ring circuit terminal 34. WVhere, as in the present instance, the base is, made in two. complementary parts, some means 1s preferv ably provided for insuring the assemblage of such parts in proper relation. In the present disclosure one of the parts, the body member 8, is formed with a transverse rib 51 to fit in a corresponding groove52 in'the cap member 9. This insures the assemblage of the parts with the terminal recess in the upper part in proper register with the finger hold recess in the lower part.

A convenient and very simple way of securing the contact ring and attached circuit terminal upon the base is to cause the binding screw 54 of such terminal to engage in a hole 55 provided for it in the base in back of the terminal. This very effectively prevents separation of these parts from the base. Additional securing means may be provided in the case of a two-piece base, such as illustrated, by causing the inner rim of the contact ring to be clamped between the two parts, substantially as indicated at 56, which will effectually prevent the ring 35 from tilting. The base may, however, be formed in one piece as shown in Fig. 5, if desired.

An opening 60 is usually provided in the base on the side opposite the ring terminal to receive the binding screw 61 of the end contact circuit terminal 15 and this opening is, as shown in Fig. 3, ofiiset from the plane of the opening 55 for the other binding screw so that said binding screws may be made as long as necessary and yet be entirely separated from each other by insulating walls.

From the foregoing it will be apparent that I have provided a swivel attachment plug of extremely simple, compact and inexpensive construction, and one whose parts are positively locked together, but at the same time can be readily separated by hand.

WVhat I claim is 1. In a two-part separable attachment plug, the combination with a terminal-carrying base and a shell contact surrounding said base, of an annular flange carried by one of said parts, a manually operable catch carried by the other one of said parts and engaging the aforesaid flange to thereby rotatably confine the partsto each other and a finger hold extending from said catch down to an exposed position at the lower contact end of the plug.

2. An attachment plug comprising a base, circuit terminals on said base, an end contact on the base connected with one of said circuit terminals, a contact ring on the base, connected with the other circuit terminal, a contact shell surrounding the base and provided with an annular flange on the end thereof bearing upon the contact ring on the base, and a spring catch on the base engaging with the said annular flange to thereby rotatably secure the screw shell upon the base.

3. An attachment plug comprising a base, circuit terminals on said base, an end contact on the base connected with one of said circuit terminals, a contact ring on the base connected with the other circuit terminal, a contact shell surrounding the base and provided with an annular flange on the end thereof bearing upon the contact ring on the base, and a spring catch carried by the contact ring on the base, engaging the flange on the screw shell to thereby rotatably confine the screw shell to the base.

4. An attachment plug comprising a base, circuit terminals on said base, an end contact on the base connected with one of said circuit terminals, a contact ring on'the base connected with the other circuit terminal, a contact shell surrounding the base and provided with an annular flange on the end thereof bearing upon the contact ring on the base, and a spring catch on the base, engaging with the said annular flange and pro vided with an exposed handle portion for manipulating the same extending below the flange when the parts are assembled.

5. An attachment plug comprising a base, an end contact carried by said base, a circuit terminal on the base connected with the said end contact, a contact ring on the base provided with an upstanding terminal post, a screw shell inclosing the base and provided with an annular flange on the end thereof arranged to bear on the contact ring on the base and a dependent spring catch carried by the aforesaid terminal post and arranged for engagement with the said annular flange on the screw shell.

6. An attachment plug comprising a base, circuit terminals and an end contact carried by said base, a screw-shell inclosing the base and provided with an inwardly-extending locking flange, and a catch on the base hav ing a shoulder arranged to interlock with the flange and provided with an exposed finger hold extending below the locking flange when the parts are assembled.

7. In an attachment plug, an insulating base having an outstanding flange at its lower end provided with a peripheral recess, a contact ring supported on said flange, a contact shell inclosing the base and having a flange at its lower end bearing on the contact ring and a spring catch carried by the base having a locking shoulder arranged to engage over the flange on the shell, and provided with a finger hold projecting down into the peripheral recess in the flange.

8. In an attachment plug, an insulating base, an angularly outstanding contact ring, carried by said base, a contact shell surrounding the base and provided with a flange at its lower end bearing on the contact ring and a spring catch carried by the base provided with a shoulder engaging over the flange on the shell and with a finger hold projecting down below the contact ring and within the outer periphery of the said ring to be thereby guarded and protected by said contact ring.

9. In an attachment plug, an insulating base, an angularly outstanding contact ring, carried by said base, and provided with a guard openingtherethrough, a contact shell surrounding the base, and provided with a flangebearing on the contact ring and a spring catch on the base provided with a I contact ring.

10. In an attachment plug, an insulating base, an angularly outstanding contact ring,

carried by said base, provided with an angularly upstanding terminal post, and with a guard opening therethrough at the base of the said terminal post, a contact shell sur rounding the insulating base and provided with a flange bearing on the contact ring,

and a dependent spring catch carried by the upstanding terminal post provided with a shoulder engaging over the flange on the shell and with a finger hold extending down through the guard opening in the contact ring.

11. In an attachment plug, an insulating base, an angular-1y outstanding contact ring carried by saidbase, provided with an angularly upstanding terminal post and with a guard opening therethrough at the base of the said terminal post, a binding'screw carried by the upper end of the terminal post, aspring catch carried by the terminal post below the said binding screw provided with an outwardly projecting locking shoulder disposed above the plane of the contact ring and with a finger hold extending down through the guard opening anol'a shell contact surrounding the insulating base, the

said shell contact having a flange bearing on the contact ring and engaged by the locking shoulder on the spring catch.

12. An attachment plug comprising an insulating base, having an opening in the side 7 thereof, an angularly outstanding contact ring carried by said base and provided with an upstanding terminal post, a binding screw carried bysaid terminal post and projecting into the opening in the side of the base to thereby prevent separation of said contact ring and terminal post from the base and a screw shell engaged on the base and provided with a flange bearing on the contact ring.

18. In an attachment plug, an insulating base, a spring catch having a broadened base portion and a narrower body portion bent upon itself to form a spring arm, the said spring arm having a finger hold portion at theend hereof and a locking shoulder adjacent to said finger hold portion, fastenings engaging the broadened base portion. for securing the spring catch upon the base, and

I a screw shell surrounding thebase provided line with the bore, an end contact'screw in said bore, extending from the contact end of the base into engagement with the said screw seat,'a second circuit terminal on the base, and a screw shell surrounding the base and in electrical connection with the said second circuit terminal.

l5.- In an attachment plug, an insulating base made in complementary parts, an angularly outstanding contact ring engaged between meeting faces of said complementary base parts, a circuit terminal seatedon one of said base parts, an end contact screw pass ing through the other base part and through a portion of the first base part into engage ment with the circuit terminal thereon to thereby secure all of the aforesaid parts in properly assembled relation, a shell contact having an end flange bearing on the contact ring, means for rotatably confining said shell contact to the base and asecond circuit terminal connected with the contact ring.

16.' In an attachment plug, an insulating base having an outstanding flange at one end thereof, a central bore opening from said flanged end into the body of the base, a longitudinally extending recess in one side 'thereof'above the end flange and a transversely extending passage extending from the side recess into'the central bore, a circuit terminal seated in the side recess and providedwith an angular foot seating in the transversely extending passage, a securing screw extending in through the central bore into engagement with the foot of the circuit terminal, 'a contact ring seated on the flange of the base, a contact shell confined to the base and bearing on said contact ring and a circuit terminal connected with the contact ring. I

17 In an attachment plug, an insulating base consisting of a terminal-carrying member having a recess on one side thereof and a cap member having a recess in the edge thereof and said two members having interfittingpartsinsuring the assemblange of said members with the recess in the one in line with the're'cess in the other, means for securing said members in properly assembled relation, a spring catch seated in therecess in the terminal-carrying member and provided with a finger hold extending down into the recess in the edge of the cap member, a shell contact surrounding the terminal carrying member and provided with 4 a flange engagedjby the spring catch and circuit terminals on said terminal-carrying member.

'18. As an article of manufacture, a contact ring for attachment plugs comprising a flat ring of sheet metal having a circular exterior and provided with a terminal post portion formed from the body of metal within the ring and connected with the ring at one edge thereof and disconnected from the ring at all other points, the said terminal post portion being bent up adjacent the point of connection with the ring, out of the plane of the ring substantially at a right angle thereto.

19. In a two-part separable attachment plug, the combination with a terminalcarrying base and a shell contact surrounding said base, of an angular flange carried by one of said parts, and a manually operable non-current carrying insulated spring catch carried by the other one of said parts and engaging the aforesaid flange to thereby rotatably confine the parts to each other, the said catch having a finger hold for operating the same exposed at the contact end of the plug.

20. In an attachment plug, an insulating base, a circuit terminal on said base, a screw shell surrounding the base, and circuit terminal, a spring catch secured to said circuit terminal and engaging the screw shell and insulating material interposed between said atch and the circuit terminal to which it is .ecured.

21. In an attachment plug, an insulating base, a centrally located end contact screw extending up through the base, a circuit terminal located at one side of a body portion of the base and engaged by the upper end of said screw, a binding screw carried by said terminal and having its axis located in a plane at one side of the longitudinal axis of the base, a second circuit terminal on the opposite side of the body portion of the base, provided with an angularly projecting contact part, a binding screw carried by said second circuit terminal and having its axis located in a plane at the opposite side of the longitudinal axis of the base from the first binding screw, the said insulating base having recesses in the body portion thereof and offset on opposite sides of the longitudinal axis of the base to receive the inner ends of the aforesaid binding screws and a contact shell engaged over the body portion of the base and bearing on the contact part of the second circuit terminal.

CLARENCE D. PLATT. Witness:

R0131. S. ALLYN.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents,

Washington, D. C. 

